| Author | Message | ||
     Treadmarks |
Checked my plugs again and I am still running a little lean. Is there some simple way to fatten up the mix across the board just a little bit? Set up is open air, k&n, race ecm and spec ops dual outlet without servo valve. | ||
| Al_lighton |
The nature of the Buell ECM is that it WILL run at 14.7:1 across the closed loop domain. When running in closed loop, it alternates between slightly rich to slightly lean, but runs on average at 14.7:1. The nature of the AFV setting algorithm demands that the map is tuned to 14.7:1 across the AFV learn domain. If you map it richer, the AFV will go down and compensate it back to 14.7:1. Theoretically, it would be possible to offset the O2 voltage by a little bit, which would make it possible for the AFV to stabilize at 100 even with a slightly richened mixture across the AFV learn domain. WHen we map, we tune the high throttle areas to 13.5:1 or so with the AFV set to 100. But we tune the closed loop domain to 14.7:1 so that the AFV doesn't get screwed up and render useless all the work that we did to get the high throttle mapping done right. I was out on my Uly yesterday on some of the steepest grades I've driven on. I tried to get it to ping, it wouldn't do it. 14.7:1 over the cruise range is OK by me, the mileage is better, the pollution less. Al | ||
| Treadmarks |
Hi Al, So, loping around and driving nice gives a 14.7, but when ya kick the pig it fattens to 13.5? | ||
| Treadmarks |
After searching I found some articles where Buellers installed TFI EFI controllers on their bikes to fatten it up after installing headers. I have one of these on my harley softail and it helped alot. Is this something that could actually work on the Buell? | ||
| Red_chili |
I considered one, as it appears to be the only way to fatten the cruise mix (fools the ECM by intercepting the O2 reading and 'altering' it). Al warned me away from it, as it tends to be imprecise, and masks problems rather than solving them, but some others like it, some don't. My Uly hasn't been surgey (new word?) enough to justify the expense. It likes it fairly lean. | ||
| Al_lighton |
"So, loping around and driving nice gives a 14.7, but when ya kick the pig it fattens to 13.5? Yup, pretty much, at least when we map it. It is important to realize that Buells stock maps aren't much different in that regard. EPA testing is done over low throttle plate angles, which happen to fall in the cruise closed loop domain. The bike runs on average at 14.7:1 there, and meets the test requirements. But the EPA doesn't constrain the WOT gas emissions, or at least not to the same levels, and the maps are richer up there. The Buell race kit will meet EPA gas emissions, but fails on noise. TFI boxes, and other in-between boxes that live between the ECM and the injectors, can be made to work. I'm not partial to them, as they operate outside the ECM control loops, including temperature. Tune them when it's hot, they're off when it's cold. Tune them when cold, they're off when it's hot. And the interaction with the closed loop AFV setting mechanisms can make tuning with them a bit of a nightmare. Since directlink operates INSIDE the control loops by only modifying the seed values in the lookup tables, it doesn't have that problem. But you still have to tune the closed loop AFV learn domain to 14.7:1 to prevent AFV skewing issues. I THINK the TFI may be capable of introducing that voltage offset to the narrow band O2 signal as I discussed above. If yes, then it MIGHT be a nice addition to a DL tuned bike that would enable the closed loop AFV learn domain to be mapped slightly richer than 14.7:1. It would take some careful testing to confirm this. Al | ||
| Teeps |
Save your money and get a race ECM or DirectLink map/reflash. I've had a TFI on my Ulysses since July/06. I can't say that there is any discernible effect with it on... at least, as judged, by my Butt-Dyno. |
